Amol Rajan: How to keep the past alive and parents out of trouble

A year ago my parents discovered local history as a hobby. They had both just retired and my fear that (in my dad's case at least) after five decades of toil they would get very bored was immediately off-set.

We have lived in Tooting, south London, for 20 years but never bothered much with its ancient origins. During this time, my mum and I would often go for walks along a beautiful road called Dr Johnson's Avenue, which dissects Tooting Bec Common. Last year, while on an enlightening local tour provided for free by volunteers, my mum discovered its etymology. This road was named after Dr Samuel Johnson, who would take walks along the old gravel path it now marks when visiting his friends Hester and Henry Thrale. The Thrales lived in nearby Streatham. Naturally, this was a revelation to my dad, who read Dr Johnson's work voraciously as a child in rural India in the 1950s.

The thought that he had raised his sons in an area stalked by Dr Johnson's ghost gave him a deep sense of fulfilment and inspiration.

My parents are now fanatical about the history of south London.

I find that for retired and old people, suddenly confronted with their own mortality, local history can provide satisfaction and belonging. But these feelings ought not to be reserved for the elderly.

I recently came across an extraordinary website called historypin.com, produced by the not-for-profit company We Are What We Do. Basically it's a series of historical and current images dropped by pin on to a Google Maps image.

Users from around the world build up, through these images, a vast picture of local heritage. What's striking is not how different things look back in a mythical past; rather, it is how similar they look in a real one.

Street corners are easily identifiable despite having different shop signs; grand architecture dominates a skyline just as it does now, even when tinged with sepia. It's often said that, as a people, we have forgotten who we are. Apparently we neither know where we've come from nor where we're going. The latter is called politics and in the absence of a consensus on it we have a duty to pursue the former, which is called history.

To the old and retired, the great consolation of local history – the history of the particular and nearby – is that it provides an exhilarating form of membership.

To the rest of us, it at least keeps our parents out of trouble.